The University of Maryland Baltimore (UMB) STAR TRACK Adolescent HIV Program (STAR TRACK Program) is a clinical and research unit with significant experience in the areas of adolescent HIV research. STAR TRACK is the only adolescent exclusive HIV service in the state of Maryland and has a comprehensive "one stop shopping" model of care, a state wide community outreach program, an HIV early identification program through an adolescent specific HIV counseling and testing unit, and a community researcher partnership Connect to Protect Baltimore. Our program has been one of 15 sites of the Adolescent HIV/AIDS Research Network (AMHARN) from 1994-2000 and the Adolescent Trials Network (ATN) from 2001 to present with a successful track record of recruitment, retention, site performance and quality assurance. At the present time, the ATN UMB unit is ranked first in recruitment out of the other 15 units nationally. Our PI, study coordinators, research assistants, and Youth Community Advisory Board member have productively participated in and contributed towards the ATN mission and its goals. Our program has extensive experience in the recruitment and retention of HIV+ and HIV- adolescents, in clinical care and research, has a caseload of 110 HFV+ youths (30 of who are in transition to adult care) and approximately 3,000 HIV-youths. STARTRACK has strong clinical and research collaborations with the two other UMB HIV clinics for adults and pediatric patients for a total of 228 active HIV infected young people under the age of 24 many of whom have research experience. Our program has highly experienced adolescent researchers and study coordinators as well as basic and clinical researchers of the Division of Pediatric Immunology and the Institute of Human Virology of the University of Maryland. These investigators have an extensive track record of leadership in multi center collaborative trials and have made significant contributions to the ATN research agenda by developing protocols and contributing in many ways to the research agenda. The tight interface between community outreach, early identification of HIV, linkage to care and research, and comprehensive primary and sub specialty care, intrinsic to STAR TRACK'S structure, facilitates the major goals of the ATN. These relationships also provide a great structure to expand subject recruitment. This application details the current clinical and research capacity of the Adolescent Medicine Trial Unit (AMTU) at the University of Maryland to conduct research protocols related to the primary, secondary and tertiary prevention of HIV. High-risk populations available for this research include high-risk sexual minority and heterosexual youths, as well as ethnic minority and substance abusing youths. In addition, it includes youths in transitional housing situations and school dropouts. Furthermore, the strong collaboration with an experienced laboratory, database manager and other University of Maryland scientists with expertise in HIV clinical trials and vaccine development provides an optimal environment for enriching the basic science and laboratory-based agenda of the ATN.